In a growing variety of business applications, it is desirable and/or necessary to convey items such as currency, documents, food, messages and other items between spaced apart locations or stations. In many situations, a somewhat flexible, yet relatively longitudinally rigid, drive tape provides a reliable yet highly adaptable drive system which minimizes the requirements for expensive and inconvenient pneumatic set-ups or long lengths of chains and/or complex gearing arrangements to adapt to twists and turns along the transport path.
For example, U.S. Pat. No. 5,054,605, herein called the '605 Patent which issued on Oct. 8, 1991 to Edward F. Bavis, shows and describes a preferred flexible drive conveyor system for use in drive-in banks and other remote transaction applications. Particularly, the Bavis '605 Patent sets forth a relatively simple and reliable conveyor system utilizing flexible tape as the drive medium. As set forth in this patent, the width and depth of the tape guide provided for the drive tape, is to be chosen to accommodate the natural tendency of the tape to bend somewhat under compression in a sinuous manner.
Additionally, U.S. Pat. No. 5,232,408, which issued to the present inventor, Michael E. Brown, sets forth an improved method of reciprocating a flexible drive tape about a cog wheel. At high speed, and/or high loads, flexible drive tapes have a tendency to fold and/or bind within the tape guides on either side of the cog wheel. The Brown '408 conveyor system provides an improved arrangement including peeler tips which significantly reduce the binding and/or folding of the drive tape as it is reciprocated about the cog wheel.
While the flexible tape drive conveyor systems disclosed in the prior Bavis and Brown patents provide many benefits over other conveyor systems known to the art, such as pneumatic and chain conveyors, flexible drive tapes in general have an additional characteristic which has heretofore limited the use of such systems. In order for a non-continuous drive tape to be both pushed and pulled within a tape guide, the drive tape must be essentially rigid in a direction transverse to the width of the tape. Thus, while the drive tape bends easily in a direction along its longitudinal axis, which allows it to curl around a cog wheel and to follow around curves and turns in the conveyor path along that longitudinal axis, the drive tape does not bend easily in a direction transverse to its width. In fact, the drive tape must have a certain amount of rigidity to optimally enable the "push and pull" requirements of a non-continuous, single drive setup.
The essential rigidity of the drive tape in at least one direction, however, has made it difficult in the past for a drive tape to be manipulated in a direction transverse to its width. Thus, it has been difficult for drive tape conveyor systems of the past to negotiate around obstructions or to make simple turns in a direction transverse to the drive tape width.
Chain link conveyors, non-rigid belt conveyors, rope conveyors and the like have been adapted to make turns in a direction both transverse to their width and their length. However, these conveyer systems require a continuous loop system because the same substantial flexibility of the drive belt (e.g. chain link, rope, canvas belt) which allows the belt to be turned in a direction transverse to its width also restricts the drive belt's ability to be both pushed and pulled without being a continuous loop or without having a drive mechanism at each end of the system.
For example, U.S. Pat. No. 1,786,343 to Griffith, shows a continuous loop flexible conveyor belt system wherein the belt is twisted through the use of rollers so that it can travel in a direction transverse to its width. However, the belt in Griffith is continuous, and, presumably, the flexibility which allows the conveyor belt to be turned in a direction transverse to its width also renders the belt too flexible to be both pushed and pulled within a guide track. Likewise, U.S. Pat. No. 4,556,143 to Johnson shows a chain link drive mechanism wherein, due to the inherent flexibility between links in the chain, the chain can be gradually turned about a large radius in the direction transverse to the chain's width, see FIG. 8 of Johnson. The chain link drive in Johnson must also be continuous, however, because the inherent flexibility between links in the chain causes the chain to substantially collapse when its direction of travel is changed unless the chain is continuous.
An endless transmission belt conveyor system for moving bobbins is shown in U.S. Pat. No. 5,097,943 to Kawasaki, et al., wherein a continuous series of ropes or belts are used to both propel the bobbins and guide them about a predetermined path. However, the belts and/or ropes disclosed in the Kawasaki, et al. patent are continuous and substantially flexible in all directions.
Hence, continuous flexible conveyor systems which can be turned in a variety of directions are known. Unfortunately, however, the flexibility which allows continuous belt, chain, or rope conveyor systems to be manipulated in a multitude of directions also makes them generally unsuitable for a non-continuous drive belt system wherein substantial rigidity is required so that a drive tape or similar drive mechanism can withstand both compressive and tensing forces without substantial buckling, stretching, and/or decreases in the tape length.
Thus there is a need for a simple, inexpensive yet reliable conveyor system for moving items between spaced apart stations wherein the conveyor system can accommodate changes in essentially all directions to negotiate around obstructions, turn comers and the like. The present invention responds to those needs.